U.S. patent application number 10/457469 was filed with the patent office on 2005-01-27 for document access control system and method.
This patent application is currently assigned to KABUSHIKI KAISHA TOSHIBA. Invention is credited to Kidokoro, Kazuaki.
Application Number | 20050021938 10/457469 |
Document ID | / |
Family ID | 34078998 |
Filed Date | 2005-01-27 |
United States Patent
Application |
20050021938 |
Kind Code |
A1 |
Kidokoro, Kazuaki |
January 27, 2005 |
Document access control system and method
Abstract
A system and method for controlling transmission of an e-mail
message includes determining whether an e-mail message being
transmitted to one or more addresses includes a link to a document,
detecting each of the one or more addresses to which the e-mail
message is being transmitted, and creating a common user account
for the detected one or more addresses. An access right to the
linked document is for each of the one or more addresses in the
common user account, and the e-mail message is transmitted with the
document link to each of the one or more addresses.
Inventors: |
Kidokoro, Kazuaki;
(Shizuoka-ken, JP) |
Correspondence
Address: |
FOLEY AND LARDNER
SUITE 500
3000 K STREET NW
WASHINGTON
DC
20007
US
|
Assignee: |
KABUSHIKI KAISHA TOSHIBA
TOSHIBA TEC KABUSHIKI KAISHA
|
Family ID: |
34078998 |
Appl. No.: |
10/457469 |
Filed: |
June 10, 2003 |
Current U.S.
Class: |
713/152 |
Current CPC
Class: |
H04L 51/00 20130101;
H04L 63/0428 20130101 |
Class at
Publication: |
713/152 |
International
Class: |
H04L 009/00 |
Claims
What is claimed is:
1. A method for controlling transmission of an e-mail message,
comprising: determining whether an e-mail message being transmitted
to one or more addresses includes a link to a document; detecting
each of the one or more addresses to which the e-mail message is
being transmitted; creating at least one user account for the
detected one or more addresses; setting an access right to the
linked document for each of the one or more addresses in the at
least one user account; and transmitting the e-mail message with
the document link to each of the one or more addresses.
2. The method according to claim 1, further comprising receiving a
request to access the document linked in the transmitted e-mail
message, the request including the address of the user requesting
the access.
3. The method according to claim 2, further comprising: referencing
the address included in the access request to the one or more
addresses in the at least one user account; and providing the user
access to the document if the address included in the access
request is an address in the at least one user account.
4. The method according to claim 3, further comprising: determining
the access right associated with the user requesting access; and
providing access to the document according to the access right.
5. The method according to claim 1, wherein the access right set
for a first address is different than the access right set for a
second address.
6. The method according to claim 1, detecting that the document
link was forwarded to another address from one of the one or more
addresses; and extinguishing the access right to the linked
document for the one address forwarding the document link.
7. A method for controlling transmission of an e-mail message,
comprising: determining whether an e-mail message being transmitted
to one or more addresses includes a link to a document; detecting
whether the linked document is encrypted; retrieving an encryption
key for decrypting the encrypted linked document; attaching the
encryption key to the e-mail message; and transmitting the e-mail
message with the document link and the encryption key to each of
the one or more addresses.
8. The method according to claim 7, further comprising receiving a
request to access the document linked in the transmitted e-mail
message, the request including the address of the user requesting
the access and the encryption key.
9. The method according to claim 8, further comprising: locating
the encrypted document in response to the reception of the access
request; and decrypting the encrypted document with the encryption
key.
10. The method according to claim 7, further comprising: detecting
each of the one or more addresses to which the e-mail message is
being transmitted; creating at least one user account for the
detected one or more addresses; and setting an access right to the
linked document for each of the one or more addresses in the at
least one user account.
11. The method according to claim 10, further comprising: receiving
a request to access the document linked in the transmitted e-mail
message, the request including the address of the user requesting
the access; referencing the address included in the access request
to the one or more addresses in the at least one user account; and
providing the user access to the document if the address included
in the access request is an address in the at least one user
account.
12. The method according to claim 7, further comprising: embedding
the encryption key with an access right to the linked document for
each of the one or more addresses; receiving a request to access
the document linked in the transmitted e-mail message, the request
including the address of the user requesting the access and the
encryption key; referencing the address included in the access
request to the one or more addresses embedded in the encryption
key; and providing the user access to the document if the address
included in the access request is an address embedded in the
encryption key.
13. A method for controlling transmission of an e-mail message,
comprising: determining whether an e-mail message being transmitted
to one or more addresses includes an attached document; detaching
the attached document from the e-mail message when a document is
attached; storing the attached document in a storage area;
detecting each of the one or more addresses to which the e-mail
message is being transmitted; creating at least one user account
for the detected one or more addresses; setting an access right to
the document for each of the one or more addresses in the at least
one user account; attaching a link to the document to the e-mail
message; and transmitting the e-mail message with the document link
to each of the one or more addresses.
14. The method according to claim 13, further comprising receiving
a request to access the document linked in the transmitted e-mail
message, the request including the address of the user requesting
the access.
15. The method according to claim 14, further comprising:
referencing the address included in the access request to the one
or more addresses in the at least one user account; and providing
the user access to the document if the address included in the
access request is an address in the at least one user account.
16. The method according to claim 15, further comprising:
determining the access right associated with the user requesting
access; and providing access to the document according to the
access right.
17. A method for controlling transmission an e-mail message,
comprising: determining whether an e-mail message being transmitted
to one or more addresses includes an attached document; detaching
the attached document from the e-mail message when a document is
attached; encrypting the detached document into an encrypted
document; creating an encryption key for decrypting the encrypted
document; attaching the encrypted document and the encryption key
to the e-mail message; and transmitting the e-mail message with the
encrypted document and the encryption key to each of the one or
more addresses.
18. The method according to claim 17, further comprising receiving
a request to access the document linked in the transmitted e-mail
message, the request including the address of the user requesting
the access and the encryption key.
19. The method according to claim 18, further comprising: locating
the encrypted document in response to the reception of the access
request; and decrypting the encrypted document with the encryption
key.
20. The method according to claim 17, further comprising: embedding
the encryption key with an access right to the linked document for
each of the one or more addresses; receiving a request to access
the document linked in the transmitted e-mail message, the request
including the address of the user requesting the access and the
encryption key; referencing the address included in the access
request to the one or more addresses embedded in the encryption
key; and providing the user access to the document if the address
included in the access request is an address embedded in the
encryption key.
21. A system for controlling transmission of an e-mail message,
comprising: a processor; and a memory, coupled to the processor,
the memory comprising a plurality of instructions executed by the
processor configured to: determine whether an e-mail message being
transmitted to one or more addresses includes a link to a document;
detect each of the one or more addresses to which the e-mail
message is being transmitted; create at least one user account for
the detected one or more addresses; set an access right to the
linked document for each of the one or more addresses in the at
least one user account; and transmit the e-mail message with the
document link to each of the one or more addresses.
22. The system according to claim 21, the memory further comprising
an instruction configured to receive a request to access the
document linked in the transmitted e-mail message, the request
including the address of the user requesting the access.
23. The system according to claim 22, the memory further comprising
instructions configured to: reference the address included in the
access request to the one or more addresses in the at least one
user account; and provide the user access to the document if the
address included in the access request is an address in the at
least one user account.
24. The system according to claim 23, the memory further comprising
instructions configured to: determine the access right associated
with the user requesting access; and provide access to the document
according to the access right.
25. The system according to claim 21, the memory further comprising
instructions configured to: detect that the document link was
forwarded to another address from one of the one or more addresses;
and extinguish the access right to the linked document for the one
address forwarding the document link.
26. The system according to claim 21, wherein the access right set
for a first address is different than the access right set for a
second address.
27. A system for controlling transmission of an e-mail message,
comprising: a processor, a memory, coupled to the processor,
comprising a plurality of instructions executed by the processor
configured to: determine whether an e-mail message being
transmitted to one or more addresses includes a link to a document;
detect whether the linked document is encrypted; retrieve an
encryption key for decrypting the encrypted linked document; attach
the encryption key to the e-mail message; and transmit the e-mail
message with the document link and the encryption key to each of
the one or more addresses.
28. The system according to claim 27, the memory further comprising
an instruction configured to receive a request to access the
document linked in the transmitted e-mail message, the request
including the address of the user requesting the access and the
encryption key.
29. The system according to claim 28, the memory further comprising
instructions configured to: locate the encrypted document in
response to the reception of the access request; and decrypt the
encrypted document with the encryption key.
30. The system according to claim 27, the memory further comprising
instructions configured to: detect each of the one or more
addresses to which the e-mail message is being transmitted; create
at least one user account for the detected one or more addresses;
and set an access right to the linked document for each of the one
or more addresses in the at least one user account.
31. The system according to claim 30, the memory further comprising
instructions configured to: receive a request to access the
document linked in the transmitted e-mail message, the request
including the address of the user requesting the access; reference
the address included in the access request to the one or more
addresses in the at least one user account; and provide the user
access to the document if the address included in the access
request is an address in the at least one user account.
32. The system according to claim 27, the memory further comprising
instructions configured to: embed the encryption key with an access
right to the linked document for each of the one or more addresses;
receive a request to access the document linked in the transmitted
e-mail message, the request including the address of the user
requesting the access and the encryption key; reference the address
included in the access request to the one or more addresses
embedded in the encryption key; and provide the user access to the
document if the address included in the access request is an
address embedded in the encryption key.
33. A system for controlling transmission of an e-mail message,
comprising: a processor, a memory, coupled to the processor,
comprising a plurality of instructions executed by the processor
configured to: determine whether an e-mail message being
transmitted to one or more addresses includes an attached document;
detach the attached document from the e-mail message when a
document is attached; store the attached document in a storage
area; detect each of the one or more addresses to which the e-mail
message is being transmitted; create at least one user account for
the detected one or more addresses; set an access right to the
document for each of the one or more addresses in the at least one
user account; attach a link to the document to the e-mail message;
and transmit the e-mail message with the document link to each of
the one or more addresses.
34. The system according to claim 33, the memory further comprising
an instruction configured to receive a request to access the
document linked in the transmitted e-mail message, the request
including the address of the user requesting the access.
35. The system according to claim 34, the memory further comprising
instructions configured to: reference the address included in the
access request to the one or more addresses in the at least one
user account; and provide the user access to the document if the
address included in the access request is an address in the at
least one user account.
36. The system according to claim 35, the memory further comprising
instructions configured to: determine the access right associated
with the user requesting access; and provide access to the document
according to the access right.
37. A system for controlling transmission an e-mail message,
comprising: a processor; a memory, coupled to the processor,
comprising a plurality of instructions executed by the processor
configured to: determine whether an e-mail message being
transmitted to one or more addresses includes an attached document;
detach the attached document from the e-mail message when a
document is attached; encrypt the detached document into an
encrypted document; create an encryption key for decrypting the
encrypted document; attach the encrypted document and the
encryption key to the e-mail message; and transmit the e-mail
message with the encrypted document and the encryption key to each
of the one or more addresses.
38. The system according to claim 37, the memory further comprising
an instruction configured to receive a request to access the
document linked in the transmitted e-mail message, the request
including the address of the user requesting the access and the
encryption key.
39. The system according to claim 38, the memory further comprising
instructions configured to: locate the encrypted document in
response to the reception of the access request; and decrypt the
encrypted document with the encryption key.
40. The system according to claim 37, the memory further comprising
instructions configured to: embed the encryption key with an access
right to the linked document for each of the one or more addresses
receive a request to access the document linked in the transmitted
e-mail message, the request including the address of the user
requesting the access and the encryption key; reference the address
included in the access request to the one or more addresses
embedded in the encryption key; and provide the user access to the
document if the address included in the access request is an
address embedded in the encryption key.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to document access
control and, more particularly, to a system and method for
controlling access to documents shared through the use of e-mail
messages.
BACKGROUND OF THE INVENTION
[0002] The increasing connectivity of computer users through local
and public networks such as LANs, WANs and the Internet, has
created a corresponding increase in the ability to share
information among users regardless of location. For example, if the
sharable information is stored at a commonly accessible location, a
user can provide access to the sharable information to another user
by providing a link to the location in an e-mail sent to the other
user. Sharing a document by providing the necessary link to it,
such as a URL, is an efficient way to share the document because it
uses far less memory then sending a copy of the original document
to all of the recipients of the e-mail. One problem, however, with
sending a link is that it may make the document accessible to
anyone capable of receiving the e-mail. This problem complicates
the document owner's responsibility to control access to the
document.
[0003] Because of this problem, the document owner may elect to
send the document itself instead of the link to the document.
Sending the document instead of the link raises access control
problems as well. The document sent is a copy of the original
document. As a result, the sent document is out of the control of
the document owner, and any subsequent changes to the original
document will not be reflected in the copy sent.
[0004] One access control system that is used to improve access
control to information is to use an encryption system. Using such a
system, original information can be encrypted in a multitude of
ways. For example, Microsoft Word (a product of Microsoft
Corporation) enables the original information to be encrypted with
a password. Whatever the encryption system, the process of
encrypting requires additional steps for users who want to share
information, and may require special knowledge of the
technology.
[0005] It would therefore be useful to provide an easy way to
handle access rights to shared information.
SUMMARY OF THE INVENTION
[0006] Briefly, in one aspect of the invention, a system and method
for controlling transmission of an e-mail message includes
determining whether an e-mail message being transmitted to one or
more addresses includes a link to a document, detecting each of the
one or more addresses to which the e-mail message is being
transmitted, and creating a common user account for the detected
one or more addresses. An access right to the linked document is
for each of the one or more addresses in the common user account,
and the e-mail message is transmitted with the document link to
each of the one or more addresses.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a block diagram of a document access system
according to an embodiment of the present invention.
[0008] FIGS. 2A and 2B are flow diagrams of a process for providing
access to a shared document according to an embodiment of the
present invention.
[0009] FIGS. 3A and 3B are flow diagrams of another process for
providing access to a shared document according to an embodiment of
the present invention.
[0010] FIGS. 4A and 4B are flow diagrams of another process for
providing access to a shared document according to an embodiment of
the present invention.
[0011] FIGS. 5A and 5B are flow diagrams of another process for
providing access to a shared document according to an embodiment of
the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0012] FIG. 1 is a block diagram of a document access system
according to an embodiment of the present invention. As shown in
FIG. 1, the document access system includes a sender workstation
10, an e-mail server 20, a user management database 30, a file
server 40, a firewall 50 and a plurality of receiver workstations
60. Each of these components may be coupled together by a network
connection or by a direct communication connection. The network
connection may be implemented by a local network, such as a LAN, or
a public network, such as the Internet.
[0013] The sender workstation 10 and receiver workstations 60 may
be a PC, a mobile phone, a PDA, a magnetic card, or some
combination thereof, or any other computing structure. Each
preferably includes a CPU, a main memory, a ROM, a storage device
and a communication interface all coupled together via a bus. The
CPU may be implemented as a single microprocessor or as multiple
processors for a multi-processing system. The main memory is
preferably implemented with a RAM and a smaller-sized cache. The
ROM is a non-volatile storage, and may be implemented, for example,
as an EPROM or NVRAM. The storage device can be a hard disk drive
or any other type of non-volatile, writable storage.
[0014] The communication interface for the sender workstation 10
and receiver workstations 60 provides a two-way data communication
coupling, such as to a network. For example, if the communication
interface is an integrated services digital network (ISDN) card or
a modem, the communication interface provides a data communication
connection to the corresponding type of telephone line. If the
communication interface is a local area network (LAN) card, the
communication interface provides a data communication connection to
a compatible LAN. Wireless links are also possible. In any such
implementation, the communication interface sends and receives
electrical, electromagnetic or optical signals, which carry digital
data streams representing different types of information.
[0015] If the network connection is an Internet connection, the
sender workstation 10 and receiver workstations 60 can transmit a
requested code for an application program through the Internet, an
ISP, the local network and the communication interface. The
received code can be executed by the CPU in the sender workstation
10 and receiver workstations 60 as it is received, stored in the
storage device, or stored in some other non-volatile storage for
later execution. In this manner, the sender workstation 10 and
receiver workstations 60 may obtain application code in the form of
a carrier wave.
[0016] Like the sender workstation 10 and receiver workstations 60,
the e-mail server 20 and file server 40 preferably include a CPU, a
main memory, a ROM, a storage device and a communication interface
all coupled together via a bus. The e-mail server 20 is configured
to enable the sender workstation 10 and receiver workstations 60 to
create e-mail messages. The e-mail server 20 is also configured to
handle the sending and receiving of e-mail messages, as well as
storing e-mail messages.
[0017] The file server 40 stores a plurality of documents in a
non-volatile storage area, such as a hard disk drive or NVRAM. For
the purposes of this application, a document can be considered any
kind of information (including in any format) that can be accessed
and/or shared by the sender workstation 10 and the receiver
workstations 60. The user management database 30 includes
information about users of documents stored in the file server 40.
In addition to information identifying the users, the user
management database 30 also includes information about the access
rights the users have to respective documents stored in the file
server 40. The information included in the user management database
30 may be stored in a non-volatile storage area, such as a hard
disk drive or NVRAM.
[0018] As shown in FIG. 1, the sender workstation 10, e-mail server
20, user management database 30 and file server 40 can all be part
of the same local network. As part of the same local network, the
firewall 50 provides protection to these devices in the local
network from unwanted access. It is also possible for each of these
devices to be independent of a local network, with access provided
by access through the Internet.
[0019] The sender workstation 10 is capable of composing an e-mail
message with the e-mail server 20, attaching to the e-mail message
a document or a link to a document stored in the file server 40,
and set access rights in the user management database 30 to the
document. In addition, the user can encrypt the document. The
document or link can be sent to one or more receiver workstations
60 by including the address of each receiver workstation 60 in the
e-mail message.
[0020] FIGS. 2A and 2B are flow diagrams of a process for providing
access to a shared document according to an embodiment of the
present invention. As shown in FIG. 2A, a user first creates an
e-mail message with a link to the document (step 202). For example,
a user at the sender workstation 10 can create the e-mail message
using the e-mail server 20 with a link to a document stored in the
file server 40. The link can be a local address corresponding to
the location where the document is stored in the storage area of
the file server 40 or a universal address, such as a URL or HTTP
address. The user also identifies each of the addresses to which to
send the e-mail message. The addresses can be e-mail addresses of
the sender workstations 60.
[0021] Before the e-mail is transmitted to the addresses identified
in the e-mail message, the system detects whether there is a link
to a document in the e-mail message (step 204). This detection can
be performed by the e-mail server 20 or whatever e-mail application
the user used to create the e-mail message. In addition to being
configured to create, send, receive and store e-mail messages, the
e-mail server 20 can be configured to analyze an e-mail message
prior to being transmitted to determine whether the e-mail message
includes a document or a link to a document.
[0022] If a link to a document is detected, each of the addresses
identified in the e-mail message are extracted (step 206). The
extraction of the addresses can also be performed by the e-mail
server 20 or e-mail application used to create the e-mail message.
The extracted addresses are then used to create a user account
(step 208). The user account includes information identifying one
or more users, such as by their addresses. The user account also
includes information identifying what rights each user has to
access a document, i.e., an access control list to the document.
The document being accessed can be a document stored in the file
server 40. The user account can be stored in the user management
database 30. The user account can be a single account storing
information for each of the users addressed in the e-mail message.
This single account can be associated with a particular document
and store information identifying access control information to the
document for one or more users.
[0023] Alternatively, the user account can be a plurality of
accounts, where each of the plurality of accounts stores
information for a respective one of the users addressed in the
e-mail message. Each of the plurality of accounts can then store
access control information for more than one document for a
respective user. In other words, each user can have a respective
user account, which stores access control information for that user
to each of one or more documents.
[0024] An access right to the linked document is set for each
address extracted from the e-mail message (step 210). The access
right defines the manner in which the recipient of the linked
document may view and/or modify the document. Examples of access
rights can be, for example, read-only and read/write access. The
access right can be set automatically to default to a particular
access right, such as read-only. Alternatively, the user sending
the link to the document can be prompted to enter what access right
to set. When prompted, the user can set the same access right for
all of the addresses or set access rights individually for each
address. The access rights are stored in the user account created
for the addresses extracted from the e-mail message. The e-mail
server 20 or e-mail application used to create the e-mail message
can be configured to create the user account and set the access
rights for the addresses extracted from the e-mail message.
[0025] Having created the user account and set the access rights,
the e-mail message with the link to the document is sent to all of
the addresses in the message (step 212). The e-mail server 20 or
e-mail application used to create the e-mail message can be
configured to control the transmission of the e-mail message, such
as from the sender workstation 10 to one or more of the receiver
workstations 60. The message can be considered transmitted once it
leaves the e-mail sender workstation.
[0026] The recipients of the e-mail message can use the provided
link to access the document. As shown in FIG. 2B, the user can
access the document by first clicking on the link in the e-mail
message (step 214). The user can click on the link using a pointing
device, such as a mouse, and depressing a key on the pointing
device when the pointer icon is over the link.
[0027] In response to clicking on the link to the document in the
e-mail message, an access request is transmitted to the location of
the document (step 216). The access request includes information
identifying the location of the document, such as by its HTTP
address, and information identifying the user sending the access
request, such as the user's e-mail address. The information
identifying the location of the document can be used to direct the
transmission of the access request. The access request is received
at the location of the document (step 218). For example, if the
e-mail message links to a document residing in the file server 20,
then the access request is transmitted to the file server 20.
[0028] Before access to the document is enabled, the user account
corresponding to the document is referenced (step 220). As
described above, the user account may be stored in the user
management database 30, which is associated with the file server 20
where the linked document is stored. The user account is referenced
to determine whether or not the user that transmitted the access
request has rights to access the document. For example, the user
that transmitted the access request is entitled to access the
document if the information identifying the user, such as the
user's e-mail address, is denoted in the user account. If the
information identifying the user is not denoted in the user
account, then the user is not entitled to access the document. This
may occur if the original recipient of the e-mail forwards the link
to the document to another address that was not among the original
addresses included in the e-mail message.
[0029] If the user transmitting the access request is entitled to
access the document, the next step is to determine what access
right the user has to the document (step 222). As described above,
the user account associated with the document identifies the access
right for each recipient address. Using the address identifying the
user transmitting the access request and the user account
information, the system can determine what access right the user
has to the linked document.
[0030] Based on the determined access right, the user is provided
access to the document (step 224). For example, if the determined
access right is read-only, then the user is only able to view the
document, but not change its contents. However, if the determined
access right is read-write access, then the user is allowed to view
the document, as well as change its contents. The system may store
the fact that a change has been made by a particular user.
[0031] As described above with respect to FIGS. 2A and 2B, a user
can send a link to a document to one or more addresses and limit
the access to the document to those addresses, as well as control
the type of access to the document. When sending an e-mail message
with a link to a document, it is possible that the document is
encrypted. If the document is encrypted, the user receiving the
link to the document may be unable to access the document.
[0032] FIGS. 3A and 3B are flow diagrams of another process for
providing access to a shared document according to an embodiment of
the present invention. As will be described below, this process
enables users receiving a link to an encrypted document to access
and view the encrypted document. As shown in FIG. 3A, a user first
creates an e-mail message with a link to the document (step 302).
As described above with respect to FIG. 2A, a user at the sender
workstation 10 can create the e-mail message using the e-mail
server 20 with a link to a document stored in the file server 40
and a list of the addresses to which to send the e-mail
message.
[0033] Before the e-mail is transmitted to the addresses identified
in the e-mail message, the system detects whether the e-mail
message contains a link to a document (step 304). If a link is
detected, the system determines whether the linked document is
encrypted (step 306). The e-mail server 20 or e-mail application
used to create the e-mail can be configured to locate the document
and determine whether or not it is encrypted. The document may be
encrypted using available encryption algorithms as are known in the
art. The present process contemplates the use of any such available
encryption algorithm.
[0034] If the document is encrypted, the encryption key for
decrypting the document is retrieved (step 308). The encryption key
depends on the type of encryption algorithm used to encrypt the
document, and it may, for example, a password or a binary key file
(used for PDP algorithms). The e-mail server 20 or e-mail
application used to generate the e-mail message can be configured
to access the file server 20 or other local files of the sender
workstation 10 to identify the location of the encryption key so it
can be retrieved. In addition to retrieving the encryption key, it
is possible to further encode the key with information about the
recipient addresses of the e-mail message. The encoding of this
address information can limit the use of the encryption key to
users associated with those addresses. The encoding of the
encryption key can also include information identifying the access
right for those addresses. The access right can be a default
setting, or the user can be prompted to identify the access right
individually for each recipient. Instead of encoding the encryption
key, it is also possible to extract the addresses, create the user
account and set the access right for each of the addresses as
described above with respect to FIG. 2A.
[0035] The retrieved encryption key is attached to the e-mail
message along with the link to the encrypted document (step 310).
The e-mail message with the link to the document and the encryption
key is then sent to each of the addresses in the message (step
312). The e-mail server 20 or e-mail application used to create the
e-mail message can be configured to control the transmission of the
e-mail message, such as from the sender workstation 10 to one or
more of the receiver workstations 60.
[0036] A user at one of the designated addresses can access the
encrypted document by clicking on the link in the e-mail message,
such as using a mouse (step 314). In response to clicking on the
link to the document in the e-mail message, an access request is
transmitted to the location of the document (step 316). The access
request includes information identifying the location of the
document, such as by its HTTP address, information identifying the
user sending the access request, such as the user's e-mail address,
and the encryption key. The information identifying the location of
the document can be used to direct the transmission of the access
request. The access request is received at the location of the
document (step 318).
[0037] The encrypted document is then located (step 320). The
location of the document can be determined form the information in
the access request. The document is then decrypted using the
encryption key included in the access request (step 322). The
manner in which the document is decrypted depends on the algorithm
used to encrypt the document. Before providing access to the
decrypted document is provided, reference can be made to the
addresses encoded with the encryption key. If the address
submitting the access request does not correspond to any of the
addresses, then no access is provided. If it does correspond to one
of the addresses, access is provided according to the access right.
The limitation to accessing the decrypted document can also be
provided by the user account, as described above with respect to
FIG. 2B.
[0038] In addition to creating an e-mail message with a link to a
document, a user can create an e-mail message with the document
attached. FIGS. 4A and 4B are flow diagrams of another process for
providing access to a shared document according to an embodiment of
the present invention in the situation where the document itself is
attached to the e-mail message. As shown in FIG. 4A, a user first
creates an e-mail message with a document attached to the e-mail
message (step 402). For example, a user at the sender workstation
10 can create the e-mail message using the e-mail server 20 with a
link to a document stored in the file server 40. The link can be a
local address corresponding to the location where the document is
stored in the storage area of the file server 40 or a universal
address, such as a URL or HTTP address. The user also identifies
each recipient addresses. The addresses can be e-mail addresses of
the sender workstations 60.
[0039] Before the e-mail is transmitted to the addresses identified
in the e-mail message, the system detects whether there is a
document attached to the e-mail message (step 304). This detection
can be performed by the e-mail server 20 or whatever e-mail
application the user used to create the e-mail message. In addition
to being configured to create, send, receive and store e-mail
messages, the e-mail server 20 can be configured to analyze an
e-mail message prior to being transmitted to determine whether the
e-mail message includes an attached document.
[0040] If an attached document is detected, the document is
detached from the e-mail message (step 406). The detachment of the
document, which removes a copy of the document from the e-mail
message, can be performed by the e-mail server 20 or the e-mail
application used to create the e-mail message. The detached
document is then stored in a storage area (step 408). The storage
area can be the file server 40 or other storage location accessible
to the sender workstation 10.
[0041] In addition to detaching and storing the document, the
system extracts identified recipient addresses in the e-mail
message (step 410), the extracted addresses are used to create a
user account (step 412), and an access right to the detached
document is set for each address extracted from the e-mail message
(step 414). The user account and access right can be created and
stored as described above with respect to FIG. 2A.
[0042] Instead of including the attached document in the e-mail
message, a link to the detached document is attached to the e-mail
message (step 416). The link corresponds to the location at which
the detached document is stored. After attaching the link, the
e-mail message with the link to the document is sent to each of the
addresses in the message (step 418). The e-mail server 20 or e-mail
application used to create the e-mail message can be configured to
control the transmission of the e-mail message, such as from the
sender workstation 10 to one or more of the receiver workstations
60.
[0043] The users at each of the addresses receiving the e-mail
message can use the link to the document in the e-mail message to
access the document in the same manner as described above with
respect to FIG. 2B. As shown in FIG. 4B, the user can access the
document by first clicking on the link in the e-mail message, such
as by using a mouse (step 420).
[0044] In response to clicking on the link to the document in the
e-mail message, an access request is transmitted to the location of
the document (step 422). The access request includes information
identifying the location of the document, such as its HTTP address,
and information identifying the user sending the access request,
such as by the user's e-mail address. The information identifying
the location of the document can be used to direct the transmission
of the access request. The access request is received at the
location of the document (step 424). For example, if the e-mail
message links to a document in the file server 20, then the access
request is transmitted to the file server 20.
[0045] Before enabling access to the document, the user account
corresponding to the document is referenced (step 426). As
described above, the user account may be stored in the user
management database 30, which is associated with the file server 20
in which the linked document is stored. The user account is
referenced to determine whether or not the user that transmitted
the access request is entitled to access the document. For example,
the user that transmitted the access request is entitled to access
the document if the information identifying the user, such as the
user's e-mail address, is denoted in the user account. If the
information identifying the user is not denoted in the user
account, then the user is not entitled to access the document. This
may occur if the original recipient of the e-mail forwards the link
to the document to another address that was not among the original
addresses included in the e-mail message.
[0046] If the user transmitting the access request is entitled to
access the document, the system determines the user's access right
to the document (step 428). As described above, the user account
associated with the document identifies the access right for each
address to which the link to the document is transmitted. Using the
address identifying the user transmitting the access request and
the user account information, the system can determine what access
right the user has to the linked document.
[0047] Based on the determined access right, the user is provided
access to the document (step 430). For example, if the determined
access right is read-only, then the user is only able to view the
document, but not change its contents. However, if the determined
access right is read-write access, then the user is allowed to view
the document, as well as change its contents.
[0048] In the process of FIG. 4A, a document attached to an e-mail
is detached from the e-mail and replaced with a link to the
document. In addition, a user account is created to limit access to
the linked document to the addresses identified in the e-mail
message. Limiting the access to the document can also be achieved
by encrypting the attached document. FIGS. 5A and 5B are flow
diagrams of another process for providing access to a shared
document according to an embodiment of the present invention by
encrypting the attached document. As shown in FIG. 5A, a user first
creates an e-mail message with a document attached to the e-mail
message (step 502). The e-mail message can be created in the same
manner as described above. Before the e-mail is transmitted to the
addresses identified in the e-mail message, the system detects
whether the existence of an attached document (step 504). If an
attached document is detected, the document is detached from the
e-mail message (step 506).
[0049] Instead of storing the document, creating a user account and
attaching a link to the document as described above in FIG. 4A, the
detached document is encrypted (step 508). As previously noted, a
variety of encryption algorithms exist that may be used to encrypt
the document as is known to those skilled in the art, and this
process may be used with any such encryption algorithm. Encryption
algorithms include, for example, PDP algorithms. In addition to
encrypting the document, an encryption key is created (step 510).
As described above, the encryption key depends on the type of
encryption algorithm used to encrypt the document. The encryption
key can be encoded with information about the recipient addresses.
The encoding of this address information can limit the use of the
encryption key to users associated with those addresses. The
encoding of the encryption key can also include information
identifying the access right for those addresses. The access right
can be a default setting, or specified by the user as prompted.
[0050] The encrypted document is then attached to the e-mail
message along with the encryption key (step 512). The attaching of
the encrypted document and encryption key can be performed by the
e-mail server 20 or the e-mail application used to generate the
e-mail message. After attaching the encrypted document and
encryption key, the e-mail message is transmitted to each of the
addresses identified in the e-mail message (step 514). The e-mail
server 20 or e-mail application used to create the e-mail message
can be configured to control the transmission of the e-mail
message, such as from the sender workstation 10 to one or more of
the receiver workstations 60.
[0051] In response to receiving the e-mail message, a user
associated with an address in the e-mail message can access the
attached encrypted document. As shown in FIG. 5B, the user clicks
on the encrypted document attached to the e-mail message (step
516). To initiate the access to the encrypted document, the user
typically will double-click on the document. If clicking on the
document does not initiate the access, it may be necessary to save
the document to a storage area, along with the encryption key and
access the document from the storage area.
[0052] After initiating the access to the encrypted document, the
encryption key is applied (step 518). The manner in which the
document is decrypted depends on the algorithm used to encrypt the
document. Before providing access to the decrypted document,
reference can be made to the addresses encoded with the encryption
key. If the address at which the user attempts to access the
encrypted document does not correspond to any of the addresses in
the e-mail message, then no access is provided. If it does
correspond to one of the addresses, then the document is decrypted.
The user is then provided with access to the decrypted document
(step 520). If the encryption key is encoded with information about
the access right to the document, then the system provides access
in accordance with the access right.
[0053] In the process of FIGS. 5A and 5B, the encrypted document is
attached to the e-mail and provided to each recipient address. It
is also possible to replace the encrypted document with the link to
the encrypted document. If the link is sent instead of the
encrypted document, then the access request to the encrypted
document would include the encryption key. The encryption key can
still have the address and access right information encoded within
it to limit the access to the encryption document. Alternatively,
at the time the document is encrypted, the system can create a user
account from the addresses in the e-mail message to control access
to the encrypted document.
[0054] In any of the foregoing embodiments, the recipient addresses
in a particular application may include alternative e-mail
addresses of that recipient based on remote access or through the
system learning alternative e-mail addresses. In addition, it is
possible to extinguish the access rights for a recipient address in
response to an action of the user at the recipient address. For
example, if a user forwards a linked or attached document to
another user, the e-mail server 20 can recognize this action and
alter the user account to extinguish the access rights for that
user.
[0055] The foregoing description of preferred embodiments of the
invention has been presented for purposes of illustration and
description. It is not intended to be exhaustive or to limit the
invention to the precise form disclosed, and modifications and
variations are possible in light in the above teachings or may be
acquired from practice of the invention. Any aspect of each
embodiment can be combined with another aspect of another
embodiment The embodiment was chosen and described in order to
explain the principles of the invention and as practical
application to enable one skilled in the art to utilize the
invention in various embodiments and with various modifications are
suited to the particular use contemplated. It is intended that the
scope of the invention be defined by the claims appended hereto and
their equivalents.
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